For a HTPC the i3 is where I'd put my money. I helped my partner's brother do a Mini-ITX HTPC build for about £450- 4gb RAM, i3-3220, Asus P8H61, 128GB Sandisk SSD, Corsair H60 and a GTX650Ti in a tiny BitFenix Prodigy Mini-ITX case. That serves as a dual-purpose HTPC and light gaming PC. As a home entertainment build running a 1080p maximum resolution, you shouldn't need to upgrade in a number of years- though you might want to pick up a 2TB external drive for storage purposes.